Coffey is a unique player in this draft. His offence at even strength was awesome and second only to Orr among dmen. My questions about him arise from the fact that he was also on the ice for a very high number of ES goals against, even in his prime. It suggests he was trading off defence for offence. OTOH, the numbers I looked at are regular season only. The Oilers as a team ha better defensive numbers in theplayoffs, so maybe Coffey could play defence when he wanted to.
Coffey's regular season +/- numbers during his prime years in Edmonton were actually really good, both relative to the league and to his teammates - he was top-5 in +/- four years in a row, and was second only to Gretzky in +/- on the team over that span. 82-86 Oilers +/-:
Gretzky: +305 (incredible)
Coffey: +220
xxxxx: +206
xxxxx: +192
Those numbers are basically the league +/- leaderboard over the same time period. That Edmonton team was killing everybody at even strength, and Coffey was Edmonton's second best +/- player, behind Gretzky. Whatever they were doing at even strength, it was working. You can say that Gretzky made those numbers, but look at Gretzky's change in scoring with Coffey's development and then later injury and departure from Edmonton (with no other major personnel changes). Here it is:
80-81: 164 points - Coffey DNP in Norris vote
81-82: 212 points - Coffey 3rd in Norris
82-83: 196 points - Coffey 5th in Norris
83-84: 205 points - Coffey 2nd in Norris
84-85: 208 points - Coffey wins the Norris
85-86: 215 points - Coffey wins the Norris
86-87: 183 points - Coffey is hurt and only plays 59 games
87-88: 149 points - Coffey is traded away
After which point, Gretzky was, himself, traded out of Edmonton. He would never again top 163 points. This also mirrors Edmonton's overall +/- during that period.
Edmonton GF/GA:
80-81: +1 - Coffey DNP in Norris vote
81-82: +122 - Coffey 3rd in Norris
82-83: +109 - Coffey 5th in Norris
83-84: +132 - Coffey 2nd in Norris
84-85: +103 - Coffey wins Norris
85-86: +116 - Coffey wins Norris
86-87: +88 - Coffey is hurt and only plays 59 games
87-88: +75 - Coffey in traded away
After which Gretzky goes, and the numbers are no longer reflective of "Edmonton without Coffey". Those numbers paint a pretty clear picture, though, both in terms of Gretzky's production and the team's GF/GA output. Paul Coffey was a huge part of that team's success, especially at even strength. Yeah, they gave up a lot of goals with Coffey on the ice, but he seems to have added about +30 to the team's goal differential and about 50 points to Gretzky's scoring totals. This sharp drop in production without Coffey makes you understand why people made such a big deal out of the trade.
Coffey's +/- numbers in Detroit were good, as well. He was 4th in team +/- his first season wearing the wheel (and led the team in +/- in the playoffs), and then 13th in the league and 1st on the team in his second, Norris winning season, which was the end of his peak.
The only phase of Coffey's peak in which his +/- is anything other than very good is the Pittsburgh years, but I think that's clearly a case of the Penguins not having the system or the personnel to deal with Coffey's style of hockey, as the article I posted indicates. Aside from the Pittsburgh years, he was always a
big even-strength plus in his prime.